Novel compositions for dental floss

ABSTRACT

This invention relates to a novel composition for use in dental flosses or tapes. More particularly, it relates to novel compositions containing a base polymer, a block copolymer and a nonmigrating compatibilizer or plasticizer that, in combination in a blend, result in a floss or dental tape having good breaking strength, elongation, tenacity, nick resistance and gentleness to the gums.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a novel composition for use in dentalflosses or tapes. More particularly, it relates to novel compositionscontaining a base polymer, a block copolymer and a nonmigratingcompatibilizer or plasticizer that, in combination in a blend, result ina floss or dental tape having good breaking strength, tenacity, nickresistance and elongation properties. It also relates to a novelextruded, flattened, monofilament tube structure useful in dental tapesand flosses, as well as a method for making such structure. It alsorelates to a flattened monofilanent tube that is textured along thelongitudinal axis as well as perpendicular to this axis.

[0003] 2. Prior Art

[0004] The use of polymer compositions in dental flosses and tapes hasbeen known previously. However, there have been continuous efforts todevelop a floss which does not shred or fray upon use and which hassufficient tensile strength for use between the teeth.

[0005] For example, U.S. Pat. No. 2,381,142 (Stonehill) describes adental floss made from a strand or filament of synthetic fibers of anunplasticized vinyl resin such as a copolymer of vinyl chloride andvinyl acetate treated with wax.

[0006] U.S. Pat. No. 3,359,344 (Fukushima) describes a method formanufacturing a spun fiber. According to Fukushima, a polymer selectedfrom the group of polyethylene, polypropylene and polystyrene having amelting point lower than 170° C. is mixed with a second polymer selectedfrom polyamides and polyesters having a melting point greater than 170°C. and an additional amount of the first polymer. The composition isblended and extruded to form a fiber.

[0007] In U.S. Pat. No. 3,639,505 (Hughes et al.), there is described amethod of improving the dyeability of polyolefin fibers and films. Themethod includes forming a polymer alloy containing a blend ofpolyolefin, a minor amount of polyethylene terephthalate and from 0.2 to5 parts per hundred parts of polymer of toluenesulfonamide compound.

[0008] U.S. Pat. No. 3,800,812 (Jaffe) describes a dental floss madefrom a polyester elastomer, including Hytrel (available from DuPont).The elastomer is extruded into a hot and tacky tape, then cooled.

[0009] U.S. Pat. No. 3,900,549 (Yamane et al.) describes a method forpreparing composite filaments composed of a polyethylene and apolyester. The method includes the steps of mixing a polyethylene havinga melt index of above 27 with a polyester having a specific inherentviscosity, the proportion of the polyethylene being 5 to 15% or 25 to90% based on the total weight of the mixture, melt extruding theresulting mixture through a spinneret and then withdrawing the extrudedfilaments at a speed of above 2,500 meters per minute.

[0010] U.S. Pat. No. 3,957,056 (Ferraro et al.) describes a dental flosscontaining aromatic polyamide fibers having at least 35% of the amidelinkages attached directly to two aromatic rings.

[0011] U.S. Pat. No. 4,552,603 (Harris, Jr. et al) describes heatbondable bicomponent fibers containing polyester and anotherthermoplastic polymer having a melting point which is at least 15% C.below that of polyester.

[0012] U.S. Pat. No. 4,583,564 (Finkelstein et al.) describes a dentalfloss consisting of filaments containing a higher melting point corematerial and a lower melting point sheath material. The sheath materialfibers are fused by subjecting them to a temperature sufficient to fusethem.

[0013] U.S. Pat. No. 4,609,710 (Iohara et al.) describes an undrawnpolyester yarn and process for manufacturing such yarn. The main acidcomponent of the yarn is an aromatic dicarboxylic acid.

[0014] U.S. Pat. No. 4,986,288 (Kent et al.) describes dental floss andtoothpicks which contain one or more coagulants to retard and stopbleeding during flossing.

[0015] U.S. Pat. No. 4,996,056 (Blass) describes a dental floss or tapecontaining fluorocarbon polymer powder particles as a solid lubricant.

[0016] Despite the existence of such products as described heretofore,there still exists a need for dental floss and tape products having highbreaking strength, high tenacity, nick resistance and suppleness whichdoes not fray or break easily when used. Furthermore, there is a need tohave dental floss or tape which is gentle to gum tissue which can bemanufactured at high speed and low cost.

[0017] It is, therefore, an object of this invention to provide anextruded, flattened, monofilament tube with rounded edges suitable foruse as a dental floss or tape.

[0018] It is another object of this invention to provide a flattened,monofilament tube that is textured along the longitudinal axis as wellas perpendicular to this axis.

[0019] It is another object of this invention to provide a polymer blendresulting in an acceptable dental floss or tape.

[0020] It is another object of this invention to provide a dental flossor tape having high breaking strength, high tenacity, nick resistanceand suppleness which does not fray or break in use.

[0021] Another object of this invention is to provide a method formaking a polymer blend resulting in an excellent composition for use indental flosses and tapes.

[0022] Another object of this invention is to provide a method of makingpolymer blend products in the form of a monofilament for use as a dentaltape or floss.

[0023] Yet another object of this invention is to provide low cost, highgrade polymer compositions for use in dental flosses and tapes.

[0024] Additional objects will become apparent throughout the ensuingdescription of the products and processes of this invention.

SUMMARY OF THE INVENTION

[0025] This invention relates to novel compositions useful in makingdental flosses and tapes. The compositions of this invention areextrudable and can be formed into a monofilament.

[0026] Dental flosses and tapes made with the novel compositions of thisinvention may be formed into an extruded, flattened, monofilament tubewith rounded edges. The unique monofilament shape provides rounded edgesthat will not cut or irritate gingiva tissue. The composition allows themonofilament to meet two primary concerns of the dental floss consumer:ease of passage between teeth and resistance to fraying. The compositionprovides a supple, slippery material that is capable of sliding andcompressing as it moves between teeth. The individual fiber composingthe novel monofilament structure and composition does not break and isnot perceived to fray as do ordinary dental flosses, which are composedof many fine monofilaments. It has been found that, upon preparation foruse, the user generally stretches the floss or tape prior to insertionbetween the teeth. We have discovered that the flosses of this inventionelongates and reduces its thickness such that it easily slides betweenthe teeth. The monofilaments of this invention can elongate at leastabout 30% of their original length and can reduce their thicknesses atleast about 10%.

[0027] The flosses of this invention can be textured along thelongitudinal axis as well as perpendicular to this axis. This texturedfloss, which still slides easily between the teeth due to its uniquecomposition, enhances the floss' effectiveness by exerting gentlepressure interstitially.

[0028] More particularly, the products of this invention relate to novelcompositions containing a base polymer, such as a polyolefins, modifiedpolyamides, polyesters or polyurethanes; block, or segmented, copolymerssuch as modified polyamides, polyesters or polyurethanes; andnonmigrating compatibilizer(s) or plasticizer(s) that in combinationresult in a polymer blend which can be formed into a monofilament havinggood breaking strength, tenacity, nick resistance and elongationproperties.

[0029] The products of this invention are considered, generally,“polymer blends”. Polymer blend technology involves the mixture ofdifferent polymers, and has been necessitated by the increasing costs ofsynthesizing new polymer structures. It has been discovered that certainpolymer blends, surprisingly, exhibit novel, unusual and unexpectedproperties different from the constituent polymers. The blending ofpolymers with careful control of the resulting blend's morphology byconsideration of the rheological and thermodynamic properties of theindividual components have led to new polymer blends of commercialinterest.

[0030] The compositions of this invention generally have threeconstituent components: a base polymer, a block copolymer and acompatibilizer. The base polymer, which is selected from the group ofpolyolefins, modified polyamides, polyesters or polyurethanes, providesstrength and tenacity; it may also impart suppleness. The segmented orblock copolymer component assists in providing nick resistance andelasticity. In general, many polymer pairs are thermodynamicallyincompatible. In order to facilitate intimate polymer blending, apolymeric compatibilizer should be introduced into the compositions ofthis invention. The compatibilizer acts as a molecular bridge betweenthe polymers, similar to the action of a surfactant in emulsifying oiland water systems. Thus, the nonmigrating compatibilizer assists inproviding integrity to the composition. This, in turn, contributes tothe suppleness of the compositions and assists in melt processing andpost-extrusion drawing of the monofilament tube by reducing meltviscosity and improving elongation characteristics.

[0031] The compositions of this invention are used in making flosses andtapes having excellent attributes. In use, dental flosses and tapes musthave a high breaking strength, high tenacity and a suitable denier andthickness. They should also have a softness or suppleness such that theycan easily be handled by the consumer. In practice, the dental floss ortape must not easily nick and break when the consumer encounters a sharpedge in flossing teeth and must not elongate too readily. The polymerblends of this invention have all of these attributes. In addition, theyare capable of being pigmented, readily processible on extruders usingtubular die or spinneret die technology and may be waxed to acceptflavors.

[0032] The products of this invention may be made by blending all theindividual polymers in pellet or powder form in a dry mixer. They arethen compounded on a twin screw compounding extruder and pelletized.Additionally, the individual polymer pellets may be gravity fed to atwin screw compounder to form the pellets of the compounded polymerblend. The compounded pellets are then extruded in a single screwextruder with a die head having an appropriate tubular or spinneret die.The extruded polymer is drawn down in a highly oriented form, annealedand calendered to achieve an appropriate thickness.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Preferably, the base polymer is a high molecular-weight polymerhaving high tensile strength, suppleness and tenacity. The base polymershould be capable of contributing these properties to the final productsuch that the resulting dental tape or floss has a tenacity (defined asstrength per unit weight) of between about 2 about 6 g/denier and, morepreferably between about 2.5 and about 3.7 g/denier. Most preferably,the tenacity of the final product should be between about 2.8 and about3.2 g/denier.

[0034] The base polymer of the compositions of this invention mayinclude polyolefins, modified polyamides, polyesters or polyurethanes.Polyolefins having suitable strength for use in the products of thisinvention are, for example, polypropylene, Valtec HH-442H (availablecommercially from Himont U.S.A. Inc., of Wilmington, Del.); modifiedpolyolefins Profax KT-012P (or its equivalent, Himont Profax KT-025P)and Profax KS-031P (available commercially from Himont U.S.A. Inc. ofWilmington, Del.); Extrall 202.01 (available commercially from ExxonCorp). One or more polymers may be used in the base polymer constituentportion of the products of this invention.

[0035] The modified polyolefins useful in the products of this inventionare preferably modified polypropylenes. Preferably, they impart twoadvantageous properties to the compositions of this invention: tenacityof the resultant floss and suppleness. Together, these propertiescontribute to the “stretchability” of the floss.

[0036] Modified polyamides having suitable strength for use in theproducts of this invention are, for example, Pebax X1147 (availablecommercially from Atochem North America of Philadelphia, Pa.).

[0037] Modified polyesters having strength suitable for use in theproducts of this invention are, for example, Hytrel G4778 (availablecommercially from Dupont Company of Wilmington, Del.). Modifiedpolyurethanes having strength suitable for use in the products of thisinvention are, for example, Estane 58091 (available commercially fromB.F. Goodrich Company of Brecksville, Ohio).

[0038] The block copolymer constituent of the compositions of thisinvention contribute to the tear strength and “nick” resistance of thefloss compositions of this invention. Thus, the compositions of thisinvention will not tear when subjected to a small cut or nick. Ratherthan permitting the tear to propagate along the product, thecompositions of this invention impede the propagation of nicks.Preferably, the block copolymer useful in the compositions of thisinvention are composed of a “hard” segment and a “soft” segment. The“hard” segments contribute to the strength of the polymer, while the“soft” segments increase its suppleness. The hard segments tend,generally, to be more compatible with each other than with the softsegments. In the composition, they tend to be attracted to each otherand form clusters. These clusters tend to impede the propagation ofnicks or cuts by standing in the path of a cut.

[0039] Preferably, the segmented or block copolymer is a modifiedpolyamide, polyester or polyurethane. Modified polyamides thatcontribute significantly to nick or cut resistance are, for example,Pebax 5533 (available commercially from Atochem North America ofPhiladelphia, Pa.). Modified polyesters that contribute significantly tonick or cut resistance are, for example, Hytrel 4056 (availablecommercially from Dupont Company of Wilmington, Del.). Modifiedpolyurethanes that contribute significantly to nick or cut resistanceare, for example, Estane 58137 (available commercially from B.F.Goodrich of Brecksville, Ohio).

[0040] The compatibilizer portion of the compositions of this inventionassist in maintaining the integrity of the compositions. They interactwith both the base polymer and the block copolymer in order to “glue”them together in the blend. This activity contributes to reducing themelt viscosity, which in turn improves processing and aids inelongation, thus maintaining the blend's suppleness at room temperature.

[0041] Preferably, the compatibilizer or plasticizer component is anonmigrating polymer. Of course, those of ordinary skill in the art willbe aware that the appropriate compatibilizer for each compositionaccording to this invention will be different, depending upon thepolymers which constitute the remainder of the composition. So long asthe compatibilizer contains substituent groups which are compatible withboth the base polymer and the block copolymer, the compatibilizer willbe an appropriate choice for use in the compositions of this invention.Nonmigrating plasticizers that contribute significantly to suppleness,reduce melt viscosity and improve drawing characteristics of theextruded monofilament are, for example, Elvaloy HP441 (availablecommercially from Dupont Company of Wilmington, Del.), a terpolymer ofethylene, carbon monoxide and butyl acrylate; Polybond 1002 (availablecommercially from BP Chemicals of Hackettstown, N.J.), a propylenepolymer having acrylic acid end groups; or Orevac 9314 (availablecommercially from Atochem North America of Philadelphia, Pa.), apropylene copolymer also having acrylic acid end groups.

[0042] The preferred compatibilizer for a composition containing apolyolefin base polymer and a polyester block copolymer is a terpolymerof n-butylacrylate, carbon monoxide and ethylene. This polymer has avery high molecular weight (about 400,000), with a low melting point(about 65° C). The amount of n-butyl acrylate present as a free monomeris about 10% maximum. The boiling point of n-butyl acrylate is about145-6° C. During processing, when temperatures of 220° C. are seen, anyremaining free monomer is volatilized and removed from the melt. Thethermal stability measured on the floss ribbon also indicates that thepolymers are stable up to about 275-300° C.

[0043] Preferably, the compositions of this invention contain as theirbase polymer one or more polyolefins. The preferable block copolymer isa modified polyester. Preferably, the compatibilizer is n-butylacrylate, ethylene, carbon monoxide terpolymer. Most preferably, thecomposition of this invention should contain Himont Profax KT-012Ppolyolefin (or its equivalent, Himont Profax KT-025P), Himont ProfaxKS-031P polyolefin, DuPont Hytrel 4056 polyester block copolymer andDuPont Elvaloy HP 441 n-butyl acrylate, ethylene carbon monoxideterpolymer.

[0044] Of course, the ranges of concentrations of the base polymer,block copolymer and compatibilizer will vary depending upon theconstituent polymers. For example, a preferred range of base polymerwhen the base polymer is polyolefin is between about 30 and about 50weight percent of the composition. In such a polyolefin-basedcomposition, a preferred range of polyester block copolymer is betweenabout 30 and 50 weight percent of the composition. The preferred rangeof compatibilizer is between about 2.5 and about 7.5 weight percent ofthe composition. In other systems, such as a polyamide system, thepreferred ranges are as follows:between about 5 and about 15 weightpercent of the base polymers, between about 10 and about 70 weightpercent of the block polyamide, and between about 3 and about 15 weightpercent of the compatibilizer.

[0045] Most polymer blends are intimate mixtures of the individualpolymers. The term “intimate” refers to the domain or size of theindividual polymers. If improperly processed, the domain size may be onthe order of tens to hundreds of microns, and may be visible to lowpower light magnification. Such a polymer blend tends to have inferiorproperties. The more intimate the mixture, the better its physicalproperties. The polymer blends of this invention are preferably madeusing techniques which result in homogeneous materials on a micro-scale.Preferably, the blends of this invention are compounded using atwin-screw compounding extruder. The use of a twin-screw extruderresults in high shear mixing in localized areas. Preferably, a WernerPfleiderer ZSK 30 or ZSK 58 twin-screw compounding extruder may be used,or an American Leistritz 40 or 34 may be used. Other twin-screwcompounding extruders known to those of ordinary skill in the art mayalso be used to compound the compositions of this invention. Otheracceptable methods of compounding the compositions of this inventioninclude batch mixers using Banbury Mills, Brabender Plasticorders or thelike.

[0046] Preferably, the flattened, tubular dental floss is produced byextruding a unique polymer blend into a small and thin tubing andsubsequently oriented (or “drawn”), annealed, collapsed (“flattened”)and wound on a spool. A double walled product, with high tensilestrength and tear, or “nick” resistance is formed. The round edges ofthe flattened tube eliminate the cause for gum irritation.

[0047] The initial diameter and wall thickness of the “as-extruded” tubeare functions of the inside and outside diameter of the female and maletubing die components.

[0048] An appropriate tubular die useful in extruding flosses has thedimensions of about 0.212 inches (outer diameter) for the male portionand about 0.222 inches (inner diameter) for the female portion. Otherdimensions may be used, in accordance with the teachings in the art,however, the aforementioned dimensions are preferred. When a spinneretdie is used, hollow filaments are extruded by the suitable arrangementand design of orifices such that the polymer melt fuses below thespinneret before entering the water quenching bath. Preferably, a“C”-shaped spinneret die is used, through which the polymer melt isextruded. As the polymer melt flows through the spinneret die andproceeds toward the cooling bath, the polymer located on the ends of the“C” fuse together and form a hollow tube. The preferable dimensions forthe “C”-shaped spinneret die are about 0.1000 inches (outer diameter)and about 0.0896 inches (inner diameter), with an allowance of about0.0200 inches between the “ends” of the “C”. Of course, other dimensionsmay be utilized in accordance with the teachings in the art. In bothmethods of forming the hollow tube or filament, gas or air can beinjected into the tube in the melt stage to help control the wallthickness.

[0049] The polymer blend is extruded through a series of zones, eachsubjecting the extruded material to a progressively higher temperaturethrough four temperature zones. For example, the first zone has atemperature of about 350° F., the second zone, about 420° F., the third,about 440° F., at which point the blend material melts and the fourth,about 470° F., at the die head. The extruded tube is then quenched in aquench bath at a temperature of about 75 to about 80° F. The resultingfiber is pulled through a series of five Godet rolls at about 20 rpms.The fiber is then pulled through a water bath at about 205° F. duringstretching. Heating the fiber quickly during stretching reduces theformation of fibrils. The fiber is then stretched in the hot water bathover a length of six feet to a second series of Godet rolls at about 145rpms. The fiber is then annealed by pulling it through an annealing ovenat 205° F. to stabilize the structure and prevent shrinking. The maximumdraw ratio of the process is about 7.25:1. The annealing process isperformed through a third series of Godet rolls at a speed of about 140rpms with the overall draw ratio being about 7:1. Other draw ratios maybe used, depending on the polymer blend composition. Other ratios usedwere: 7.0:1.0 maximum and 6.5:1.0 overall; 6.75:1.00 maximum and6.25:1.00 overall. The filament is then calendered, flattened and woundup onto spools for subsequent waxing and made into bobbins for consumeruse.

[0050] Preferably, the dimensions of the flattened, tubular monofilamentare between about 2 and about 4.5 mils in thickness and, the widthbetween about 0.025 to about 0.070 inches when the denier is in therange of about 700 to about 900. Most preferably, the monofilament isabout 2.5 mils to about 3 mils in thickness at this denier. When higherdeniers are used, e.g., from about 1200 to about 1300, the preferredthickness is between about 2 mils and about 4.5 mils, but the widthshould preferably be between about 50 mils and about 80 mils. When thedenier range is in the range of between about 600 and about 900, thepreferred thickness should be between about 2 mils and about 4.5 milsand the width should be between about 25 and about 35 mils. This enablesus to make ribbons or tapes with a broad range of widths suitable foruse in dental hygiene.

[0051] Referring to FIG. 1, there is illustrated a method of makingflosses and dental tapes of this invention. Polymer blend pellets arefed into a dryer/feed hopper, 10, through which the resin travels to anextruder, 20. The polymer is extruded through a die head, 30, forming amonofilament, and is then deposited into a water quench bath, 40. Waterquench bath 40 should be kept at a temperature relatively lower than thetemperature of the polymer resin as it exits the extruder 20. Forexample, water quench bath 40 may be kept at about 70° F. Aftertravelling through water quench bath 40, the monofilament is drawnthrough Godet A, 50, which causes the monofilament to elongate. Godet A,50, should run at a speed of about between 10 and 50 revolutions perminute (RPM). More preferably, Godet A should run at a speed of betweenabout 20 RPMS. The monofilament is then drawn through a hot water bath,60. Hot water bath 60 should be kept at about 150 to about 210° F. Mostpreferably, it should be kept at about 205° F. After passing through hotwater bath 60, the monofilament is drawn through another set of Godetrolls, Godet B, 70, for further extension. Godet B, 70, should run at aspeed of between about 130 and about 200 RPM. The speed differentialbetween Godet A, 50, and Godet B, 70, and passing the monofilamentthrough hot water bath 60 assists in elongating the monofilament withoutbreaking it or causing nicks or tears in the filament. From Godet B, 70,the monofilament is routed through annealing oven 1, 80, which is heldat about 250° F. and then through annealing oven 2, 90, which is held atabout 205° F. This portion of the process assists in stabilizing thecompositions of the invention, strengthening the monofilament. Themonofilament is then routed through Godet C, 100, which is run atbetween about 125 and about 140 RPM. Preferably, the monofilament isflattened through calender 110 and then wound around a spool at rewindstation 120.

[0052] The following examples serve to illustrate the compositions andmethods of this invention, however, it should be understand that thecompositions and methods of this invention are not limited to theillustrated embodiments.

EXAMPLE 1

[0053] 2550 grams of Extrall 202.01 from Exxon Corporation, athermoplastic polyolefin believed to be polypropylene modified in areactor process with a thermoplastic rubber, 300 grams of Hytrel 4056available from the E.I. dupont de Nemours Corporation of Wilmington,Del., a block copolymer consisting of polybutylene terephthalate andpolyether glycols, and 150 grams of Elvaloy HP441 from the DupontCorporation, a terpolymer made from ethylene, butylacrylate and carbonmonoxide monomers, were tumble-blended in a vee blender. The compositionwas compounded and pelletized on a Werner Pfleiderer ZSK-30 twin screwcompounding extruder and subsequently extruded into a monofilament in aKillion (¼inch) single screw extruder with a tubular die head. Theextruded polymer was drawn down, annealed and calendered. The resultingpolymer monofilament had reasonable physical properties. Denier,thickness, width, maximum force to break and maximum elongation andtenacity are shown in Table 1. Denier was determined by measuring alength of floss and multiplying to assess the weight of the floss per9000 meters of filament. Thickness was determined by using a micrometer.Width was measured using a shadowgraph. Breaking strength and percentelongation were determined using the procedures set forth in ASTM D2256,with the samples tested under TAPPI conditions (i.e. 73° F. and 60%relative humidity). Examples 2-6 and 8-35 were similarly tested. Theresults are set forth in Table I.

EXAMPLES 2 AND 3

[0054] Polymers were blended, pelletized, extruded and drawn down asdescribed in Example 1. The components and respective percentages areshown in Table 2. TABLE 2 Example 2 Example 3 Extrall 202.01 80 80Hytrel 4056 10 15 Elvaloy HP441 10 5

EXAMPLES 4, 5 AND 6

[0055] To test the significance of the amount of block copolymer (Hytrel4056) had on nick resistance, polymers having varying amounts of blockcopolymer were blended, pelletized, extruded and drawn (as in Example1); the compositions are shown in Table 3. TABLE 3 Example 4 Example 5Example 6 Extrall 202.01 75 55 35 Hytrel 4056 20 40 60 Elvaloy HP441 5 55

EXAMPLES 7 AND 8

[0056] Monofilaments were made in accordance with the proceduredescribed in Example 1. The compositions of Examples 7 and 8 containedAmpacet 11343 from the Ampacet Company, a white pigmented (TiO2)polypropylene concentrate, and are shown in table 4. TABLE 4 Example 7Example 8 Extrall 202.01 72.5 70.0 Hytrel 4056 20.0 20.0 Elvaloy HP4412.5 5.0 Ampacet 11343 5.0 5.0

EXAMPLES 9 AND 10

[0057] Monofilaments were made as described in Example 1. Thecompositions, which contain Polybond 1002 from BP Chemicals Company, aplasticizer a polypropylene grafted with acrylic acid, are set forth inTable 5. TABLE 5 Example 9 Example 10 Extrall 202.01 72.5 70.0 Hytrel4056 20.0 20.0 Polybond 1002 2.5 5.0 Ampacet 11343 5.0 5.0

EXAMPLES 11 AND 12

[0058] Monofilaments were made as described in Example 1 having thecompositions, which contain Hytrel G4778, a block copolymer consistingof polybutylene phthalate and polyetherglycols, are shown in Table 6.TABLE 6 Example 11 Example 12 Extrall 202.01 72.5 70.0 Hytrel G4778 20.020.0 Elvaloy HP441 2.5 5.0 Ampacet 11343 5.0 5.0 Examples 13, 14 and 15

[0059] Modified polyolefin base polymers were evaluated. These polymers,Himont KS-021P, KS-031P, KS-052P and KS-063P are ethylene propylenepolymers. KT-012P is a terpolymer which also contains ethylene andpropylene. The compositions are shown in Tables 7-12. TABLE 7 Example 13Example 14 Example 15 Himont KS-021P 70 — — Himont KS-031P — 70 — HimontKS-052P — — 70 Hytrel 4056 20 20 20 Elvaloy HP441  5  5  5 Ampacet 11343 5  5  5

[0060] TABLE 8 Example 16 Example 17 Himont KS-031P 65 55 Hytrel 4056 2535 Elvaloy HP441 5 5 Ampacet 11343 5 5

[0061] TABLE 9 Example Example 18 Example 19 Example 20 21 HimontKS-063P 25 35 49 70 Himont KS-031P 50 35 21 — Hytrel 4056 15 20 20 20Elvaloy HP441 5 5 5 5 Ampacet 11343 5 5 5 5

[0062] TABLE 10 Example 22 Example 23 Example 24 Himont KT-012P 25 35 45Himont KS-031P 50 35 25 Hytrel 4056 15 20 20 Elvaloy HP441 5 5 5 Ampacet11343 5 5 5

[0063] TABLE 11 Example Example 25 Example 26 Example 27 28 HimontKT-012P 45 20 45 20 Himont KS-031P 20 45 10 35 Hytrel 4056 25 25 35 35Elvaloy HP441 5 5 5 5 Ampacet 11343 5 5 5 5

[0064] TABLE 12 Example 29 Example 30 Himont KT-012P 20 25 HimontKS-031P 45 35 Hytrel 4056 25 35 Elvaloy HP441 5 5 Ampacet 11343 5 5

EXAMPLES 31 AND 32

[0065] A plasticizer, Elvaloy 742, was used in the compositions ofExamples 31, 32, 33, 34 and 35. Elvaloy 742 contains ethylene, vinylacetate and carbon monoxide. The compositions were made in accordancewith the procedure set forth in Example 1. The compositions of Examples31 and 32 are set forth in Table 13. The compositions of Examples 33, 34and 35 are set forth in Table 14. The polymer blends of Examples 33, 34and 35 were tumbled-blended in a vee-blender.

[0066] The compositions were compounded and pelletized on an AmericanLeistritz ASE-50 twin screw compounding extruder and subsequentlyextruded into a monofilmanet tube in a David-Standard (1¼inch singlescrew) extruder with a spinneret “C”-shaped die. The extruded polymerwas quenched, drawn down, annealed and calendered. The resulting polymermonofilments had good physical properties (See Table I). TABLE 13Example 31 Example 32 Himont KT-012P 20 20 Himont KS-031P 35 25 HytrelHTR-6108 35 45 Elvaloy 742 5 5 Ampacet 11343 5 5

[0067] TABLE 14 Example 33 Example 34 Example 35 Himont KT-012P 45 35 20Himont KS-031P — 10 25 Hytrel 4056 45 45 45 Elvaloy HP441 5 5 5 Ampacet11343 5 5 5

[0068] The floss of Example 33, in its relaxed state, had a thickness of0.0030 inches. The floss was prepared for use by wrapping the endsaround two fingers prior to insertion in the mouth. The floss wassubjected to a slight tension and measurement of the thickness taken.The floss, when under slight tension, measured 0.0026 inches inthickness, a reduction of about 13%. In contrast, in most traditionalmonofilament flosses such as expandable Teflon, the elongation of themonofilament under such tension is about 3- 5% without any measurablereduction in thickness.

EXAMPLE 36

[0069] Monofilaments were made as described in Example 33, 34 and 35;the composition shown in table 15 contained Pebax 5533 and X1147, bothmodified polyamides, and Orevac 9314, a compatibilizer (all availablecommercially from Atochem North America of Philadelphia) and Unitane OR450, Titanium Dioxide. TABLE 15 Pebax 5533 80.0 Pebax X1147 7.2 Orevac9314 10.8 Unitane OR 450 2.0

EXAMPLES 37 AND 38

[0070] Tables 16 and 17 show compositions made in accordance with theprocedure set forth in Examples 33, 34 and 35 containing Pebax 6333, amodified polyamide (available commercially from Atochem North America ofPhiladelphia) as the base polymer in the compositions of this invention.TABLE 16 Pebax 6333 80.0 Orevac 9314 18.0 Unitane OR 450 2.0

EXAMPLE 38

[0071] TABLE 17 Pebax 5533 80.0 Pebax X1147 7.2 Orevac 18211 10.8Unitane OR 450 2.0

EXAMPLE 39

[0072] Table 18 show compositions made in accordance with the procedureset forth in Examples 33, 34 and 35 containing Himont KT-025P, aproprietary terpolymer which is commercially from the Himont Co. ofWilmington, Del., Hytrel 4056, Elvaloy HP441 and pigment. TABLE 18Himont KT-025P 45.0 Hytrel 4056 45.0 Elvaloy HP441 5.0 Pigment 5.0

[0073] TABLE 1 EX- MAXI- TENA- AMPLE TRICKI- MUM CITY NUM- DEN- NESSWIDTH BREAK E- % BER IER (INCH) (INCH) STRENGTH LONG g/D 1 1269 0.00390.0684 6.63 21.8 2.37 2 1129 0.0039 0.0560 6.42 18.5 2.58 3 1190 0.00430.0555 7.00 19.4 2.67 4 1136 0.0047 0.0484 6.30 31.9 2.51 5 1143 0.00320.0671 6.50 32.3 2.58 6 1168 0.0042 0.0521 6.08 50.7 2.36 7 [NO DATA FOREXAMPLE available] 8 1382 0.0079 0.0390 7.46 46.1 2.45 9 1915 0.00860.0518 9.87 56.0 2.34 10 2415 0.0086 0.0510 9.87 56.0 1.86 11 14390.0086 0.0417 8.77 60.1 2.77 12 1058 0.0073 0.0358 5.83 35.5 2.50 131000 <5.00 14 950 <5.00 15 900 <5.00 16 960 <5.00 17 950 <5.50 18 960<5.00 19 940 <5.00 20 960 <5.00 21 940 <5.00 22 960 <5.00 23 1000 6.0024 960 5.80 25 950 <5.50 26 960 <5.50 27 950 5.50 28 960 5.50 29 930<5.50 30 970 5.50 31 960 <5.00 32 950 5.50 33 970 0.0370 0.0450 7.1341.7 3.34 34 938 0.0380 0.0500 6.15 62.1 2.98 35 970 0.0350 0.0510 5.1153.6 2.39

What is claimed is:
 1. A composition for making dental hygiene devicescomprising a polymer blend comprising base polymer, a block copolymerand a compatibilizer.
 2. A composition according to claim 1 wherein saidbase polymer is selected from the group consisting of polyesters,polyolefins, polyamides, polyurethanes and block copolymers ofpolyesters, polyamides and polyurethanes.
 3. A composition according toclaim 2 wherein said base polymer is a polyester or a block copolymer ofa polyester.
 4. A composition according to claim 2 wherein said basepolymer is a polyolefin or a block copolymer of a polyolefin.
 5. Acomposition according to claim 2 wherein said base polymer is apolyamide or a block copolymer of a polyamide.
 6. A compositionaccording to claim 2 wherein said base polymer is a polyurethane or ablock copolymer of a polyurethane.
 7. A composition according to claim 1wherein said block copolymer is selected from the group consisting ofpolyamides, polyester and polyurethanes.
 8. A composition according toclaim 7 wherein said block copolymer is a polyamide.
 9. A compositionaccording to claim 7 wherein said block copolymer is a polyester.
 10. Acomposition according to claim 7 wherein said block copolymer is apolyurethane.
 11. A composition according to claim 1 wherein saidcompatibilizer is a terpolymer comprising ethylene, carbon monoxide andbutyl acrylate.
 12. A composition according to claim 1 wherein saidcomposition comprises between about 30 and about 50 weight percent basepolymer comprising a polyolefin, between about 30 and about 50 weightpercent polyester block copolymer and between about 2.5 and about 7.5weight percent of a compatibilizer.
 13. A composition according to claim1 wherein the base polymer is a polyamide or a block copolymer of apolyamide in which the preferred range is between about 5 and 15 weightpercent, between 10 and 10 weight percent of the block polyamide, andbetween 3 and 15 weight percent of the compatibilizier.
 14. A dentalhygiene device made from the composition of claim 1 wherein said devicecomprises a flattened, tubular floss.
 15. A dental hygiene deviceaccording to claim 14 wherein said flattened, tubular floss has roundedlongitudinal edges.
 16. A dental hygiene device according to claim 14wherein said floss comprises a coating of wax chosen from the groupconsisting of microcrystalline wax or beeswax.
 17. A dental hygienedevice according to claim 16 wherein said waxes contain one or moreflavors.
 18. A dental hygiene device according to claim 17 wherein saidflavors are selected from the group consisting of mint, cinnamon andbubble gum.
 19. A dental hygiene device according to claim 16 whereinsaid waxes contain therapeutic compounds.
 20. A dental hygiene deviceaccording to claim 19 wherein said therapeutic compounds comprise one ormore compounds selected from the group consisting of sodium fluoride,cetyl pyridium chloride and chlorhexidine gluconate.
 21. A compositionaccording to claim 1 wherein said polymer blend further comprise containpigments to impart colors to said polymer blend.
 22. A compositionaccording to claim 1 wherein said polymer blends contain stabilizers.23. A composition according to claim 1 wherein said polymer blendscontain mineral fillers.
 24. A process for making a tubular dentalhygiene device comprising: a) extruding a polymer blend into a small andthin tubing using an extrusion pump; b) orienting said polymer blend; c)annealing said polymer blend; and d) collapsing said polymer blend. 25.A process according to claim 24 wherein, during said extrusion step, theextrusion pump is rhythmically pulsed, thereby producing a texturedtubing.
 26. A process according to claim 24 wherein said polymer blendis extruded into a cooling bath having a temperature of between about 75and about 80° F.
 27. A process according to claim 24 wherein after saidextrusion step, said polymer blend is heated and pulled through Godetrolls.